Seismic wave Propagation and Imaging in Complex media

Seismic wave Propagation and Imaging in Complex media: a European network Steffen Abe Experienced Researcher Host Institution: UCD, Dublin Place of Origin: Jena, Germany Appointment Time: October 2005 Project: Simulation of Rupture Propagation using DEM Task Groups: Local Scale Cooperation: Mid-Term Review Meeting, February 13 -14, Tutzing www. spice-rtn. org

Project Scope Using DEM for the simulation of rupture propagation Discrete Element Methods can be used to model complicated, discontinous geometries, such as small scale surface roughness on a fault surface. DEM simulation of fault slip can give insight into influence of small scale geometric heterogeneity on fault behaviour Mid-Term Review Meeting, February 13 -14, Tutzing www. spice-rtn. org

Main Results Simulations so far have reproduced some aspects of seismicity on real faults using relatively simple fault models (1 -3 “rough” sections on straight fault) ➔ realistic rupture velocities ➔ a range of event sizes ➔ complex slip distributions ➔nucleation of large event in rough patches (asperities) slip velocity distribution vs. time for a large event Mid-Term Review Meeting, February 13 -14, Tutzing www. spice-rtn. org

Outlook In order to get more realistic results, more complex fault geometry is neccesary ➔ heterogeneity on a wider range of scales ➔non-straight fault ➔ 3 D Additional analysis simulation results: ➔ stress changes ➔ event statistics of Mid-Term Review Meeting, February 13 -14, Tutzing the www. spice-rtn. org